The original patent describes how images may be recorded confocally using available color-capable matrix receivers. This arrangement makes it possible to scan rapidly many particles simultaneously in three dimensions and multiple spectral ranges, for example tissue cells, on the basis of fluorescing and/or dyed sites in medical applications. In the original patent, provision is made for the required motion in the z axis (focusing-through ) of the cells where the latter are located on a slide, and the slide is moved along the optical axis (z direction) by mechanical means. As a result, one plane after the other of the sample (typically cells with the cell nucleus, cell plasma, etc.) is imaged as it is focused on the radiation receiver.
Many diagnostic methods in medicine employ flow-through systems. Cells are fed to these instruments in a suspension. They are pumped through a flow-through cuvette (often called a cannula or capillary tube) which is located in an optical path. Using suitable illumination, the fluorescence, absorption, and scatter properties for example of the sample are automatically recorded. A great number of cells from one patient may be quickly examined with well-known instruments, and a statistical analysis of the optical properties of the cells may be created automatically. However, these flow-through systems have the disadvantage that the cells cannot be imaged.
The object of the present invention (application for patent of addition) is therefore to show how flow-through systems may be equipped with a capability to record high-resolution, confocal images. For this purpose, the invention provides that the flow-through cuvette (300)(or capillary tube or cannula) is located on the optical path of the imaging system at an angle inclined to its focal plane (13f). This arrangement achieves the goal that the cells are automatically brought into different focal planes of the optical system as a result of the flow of the fluid.